Return the tp_flags member of type. This function is primarily
meant for use with Py_LIMITED_API; the individual flag bits are
guaranteed to be stable across Python releases, but access to
tp_flags itself is not part of the limited API.

New in version 3.2.

Changed in version 3.4: The return type is now unsignedlong rather than long.

Finalize a type object. This should be called on all type objects to finish
their initialization. This function is responsible for adding inherited slots
from a type’s base class. Return 0 on success, or return -1 and sets an
exception on error.

Creates and returns a heap type object from the spec. In addition to that,
the created heap type contains all types contained by the bases tuple as base
types. This allows the caller to reference other heap types as base types.

Return the function pointer stored in the given slot. If the
result is NULL, this indicates that either the slot is NULL,
or that the function was called with invalid parameters.
Callers will typically cast the result pointer into the appropriate
function type.